Abstract

Purpose

Distal thoracic kyphosis (DTK) equivalent to proximal lumbar lordosis (PLL) is the sum of pelvic tilt (PT) and the difference (Δ) between lumbar lordosis (LL) and pelvic incidence (PI): PLL = DTK = PT + Δ. With the assumption that proximal thoracic kyphosis (PTK) is similar to DTK, we propose the equation TK = 2(PT + LL − PI) to express the relationship between thoracic kyphosis (TK) and pelvic parameters. The objective of this work is to verify this relationship in a normal population.

Methods

Full spine radiographs of 100 adolescents and young adults (13 to 20 years old), free from vertebral pathology, were analyzed. Measurements included pelvic parameters, LL, PLL, DLL, TK, PTK, DTK and C7 global tilt. The measured global TK was compared with the theoretical TK calculated according to the formula TK = 2(PT + LL − PI).

Results

The difference between measured TK and calculated TK was + 2.3° and correlated with the C7 global tilt (r = 0.86). There was a significant linear regression between TK and PT + ∆ (p < 0.0001). Given radiographs’ inter-rater reliability of 5° for angled measurements, the p value (0.047) between measured TK and calculated TK is statistically significant to support the hypothesis.

Conclusion

This work validates the formula TK = 2(PT + LL − PI) which allows the calculation of global TK as a function of PT, LL and PI. This calculated TK can be used as a target for sagittal correction of adolescents with spine deformities.

Graphic abstract

These slides can be retrieved under Electronic Supplementary Material.

中文翻译：

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腰盆参数可以用来预测青少年的胸椎后凸畸形。

摘要

目的

相当于近端腰椎前凸（PLL）的远端胸椎后凸畸形（DTK）是骨盆倾斜度（PT）和腰椎前凸畸形（LL）与骨盆发病率（PI）之差（Δ）的总和：PLL = DTK = PT +Δ。假设胸椎后凸畸形（PTK）与DTK相似，我们提出方程TK = 2（PT + LL-PI）来表达胸椎后凸畸形（TK）与骨盆参数之间的关系。这项工作的目的是验证正常人群中的这种关系。

方法

分析了没有椎骨病理的100名青少年和13岁至20岁的年轻人的全脊柱X线照片。测量包括骨盆参数，LL，PLL，DLL，TK，PTK，DTK和C7整体倾斜度。将测得的整体TK与根据公式TK = 2（PT + LL-PI）计算的理论TK进行比较。

结果

测量的TK与计算的TK之间的差异为+ 2.3°，并且与C7整体倾斜度相关（r  = 0.86）。TK和PT + ∆之间存在显着的线性回归（p  <0.0001）。给定X射线照片的角度测量的评定者间可靠度为5°，测量的TK和计算的TK之间的p值（0.047）在统计学上很有意义，以支持该假设。

结论

这项工作验证了公式TK = 2（PT + LL-PI），该公式允许根据PT，LL和PI计算全局TK。计算出的TK可以用作脊柱畸形青少年矢状面矫正的目标。

图形摘要

这些幻灯片可以在电子补充材料下找到。